<template>
  <div :class="className" :style="{height:height,width:width}" />
</template>

<script>
import echarts from 'echarts'
require('echarts/theme/macarons') // echarts theme
import { debounce } from '@/utils'

export default {
  props: {
    className: {
      type: String,
      default: 'chart'
    },
    width: {
      type: String,
      default: '100%'
    },
    height: {
      type: String,
      default: '350px'
    },
    autoResize: {
      type: Boolean,
      default: true
    },
    chartData: {
      required: true
    },
    legend: {
      type: Array,
      default() {
        return []
      }
    },
    xAxis: {
      type: Array,
      default() {
        return []
      }
    }
  },
  data() {
    return {
      chart: null,
      sidebarElm: null,
      seriesList: []
    }
  },
  watch: {
    chartData: {
      deep: true,
      handler(val) {
        this.setOptions(val)
      }
    }
  },
  mounted() {
    this.initChart()
    if (this.autoResize) {
      this.__resizeHandler = debounce(() => {
        if (this.chart) {
          this.chart.resize()
        }
      }, 100)
      window.addEventListener('resize', this.__resizeHandler)
    }

    // 监听侧边栏的变化
    this.sidebarElm = document.getElementsByClassName('sidebar-container')[0]
    this.sidebarElm && this.sidebarElm.addEventListener('transitionend', this.sidebarResizeHandler)
  },
  beforeDestroy() {
    if (!this.chart) {
      return
    }
    if (this.autoResize) {
      window.removeEventListener('resize', this.__resizeHandler)
    }

    this.sidebarElm && this.sidebarElm.removeEventListener('transitionend', this.sidebarResizeHandler)

    this.chart.dispose()
    this.chart = null
  },
  methods: {
    getRandomColor() {
      return '#' + (function fn(color) {
        return (color += '0123456789abcdef'[Math.floor(Math.random() * 16)]) && (color.length === 6) ? color : fn(color)
      })('')
    },
    sidebarResizeHandler(e) {
      if (e.propertyName === 'width') {
        this.__resizeHandler()
      }
    },
    setOptions(data) {
      for (const key in data) {
        if (data.hasOwnProperty(key)) {
          const element = data[key]
          const _data = []
          for (const key1 in element) {
            _data.push(element[key1])
          }
          this.legend.push(key)
          const series = {
            name: key,
            itemStyle: {
              normal: {
                color: this.getRandomColor(),
                lineStyle: {
                  color: this.getRandomColor(),
                  width: 2
                }
              }
            },
            smooth: true,
            type: 'line',
            data: _data
          }
          this.seriesList.push(series)
        }
      }
      const option = {
        xAxis: {
          data: this.xAxis,
          boundaryGap: false,
          axisTick: {
            show: false
          }
        },
        grid: {
          left: 50,
          right: 50,
          bottom: 20,
          top: 30,
          containLabel: true
        },
        tooltip: {
          trigger: 'axis',
          axisPointer: {
            type: 'cross'
          },
          padding: [5, 10]
        },
        yAxis: {
          axisTick: {
            show: false
          }
        },
        legend: {
          data: this.legend
        },
        series: this.seriesList
      }
      this.$emit('legend', this.legend)
      this.chart.setOption(option)
    },
    initChart() {
      this.chart = echarts.init(this.$el, 'macarons')
      this.setOptions(this.chartData)
    }
  }
}
</script>
